The present invention relates to automated sewing machines, and particularly to an X-Y fabric orientating mechanism.
Both automatic and semi-automatic sewing machine systems for performing predetermined stitch patterns on fabric pieces are well known in the prior art. Basically, these systems employ an industrial sewing machine, a microprocessor or equivalent control device and an orientating mechanism for moving the fabric under the needle of the sewing machine in response to commands from the control device.
The orientating mechanism in some of these systems secures the fabric piece and moves it in a two dimensional orthogonal field. Competition has dictated that speeds of 1800 or more stitches per minute must be attained and at the same time maintain a high stitch quality. That is, all stitches are the same length as predetermined, they are formed in the proper manner, etc.
In order to satisfy these demands, various steps are taken. The two dimensional orientating mechanism is actuated by means of stepper motors operative when the needle is withdrawn from the material so as to incrementally step the fabric between stitching cycles. That is, the fabric piece is generally stationary from the time the needle enters it until it is withdrawn. Cables or like flexible means are used to connect the frame mounted stepper motors to the separate X and Y carriages. Structural rigidity and low inertia forces are the objectives to be achieved.
But, as the demand to sew larger and larger fabric pieces increases, so do the problems with designing and manufacturing a stucturally rigid system which has a low inertia.